GATE 2013 · session-1
The procedure below must find and replace characters in input array A. Characters to be replaced are in oldc, and their respective replacements are in newc. A has five characters; oldc and newc have three each. However, the procedure is flawed.
c
The four test cases are:
(1) oldc="abc", newc="dab"
(2) oldc="cde", newc="bcd"
(3) oldc="bca", newc="cda"
(4) oldc="abc", newc="bac"
The tester tests the program on all input strings of length five consisting of characters a, b, c, d and e with duplicates allowed. With the four test cases above, how many test cases will be able to capture the flaw?
void find_and_replace (char *A, char *oldc, char *newc) {
for (int i=0; i<5; i++)
for (int j=0; j<3; j++)
if (A[i] == oldc[j]) A[i] = newc[j];
}